RNA extraction using self-made guanidinium-acid-phenol reagents

RNA extraction with guanidinium-acid-phenol reagents based on the research of Chomczynski P, Sacchi N. 1987 [1] and reviewed by the authors again in 2006 [2] is generally considered the extraction method that gives the best quality RNA. If you prefer using ready-made reagents like TRIzol (Invitrogen product name) or the equivalent TRI (Sigma-Aldrich product name) refer to this protocol page: RNA extraction using trizol/tri.